Automobile servicing lift



P. J. LUNATI AUTOMOBILE SERVICING LIFT Jan. 19, 1932.

6 Sheets-Sheet l Filed Jan. 14, 1927 E FW P. J. L'UNATI AUTOMOBILE SERVICIN'G LIFT 6 Sheets-Sheet 2 Filed Jan. 14. 1927 Jan. 19, 1932.

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AUTOMOBILE SERVICING LIFT Filed Jan. 14. 1927 6 Sheets-Shee 4 Jan. 19, 1932.

P. J. lLUNATI AUTOMOBILE SERVICING LIFT Filed Jan. 14. 19,27 6 Sheets-Sheet 5 @wwwa w, wf/

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P. J. LUNATI AUTOMOBILE SERVICING LIFT 192'? 6 Sheets-Sheet 6 A Filed Jan. 14.

Jan. 19, 1932.

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Patented Jan. 1,9, 1932 I PETER LUNATI, OF MEMPHIS, TENNESSEE y AUTQMOBLE SERVICING LIFT appueema eiee rename ie, we?, semi no. renier.

This invention relates to hydraulic automobile-servicing lifts, and is an improvement over the structures shown in my prior Patent No. 1,552,326, granted September lst,

1925, and my copending applications Serial ftion of the device to permit the owner thereil NOS. 36,019, filed June 9th, i925, Patent Ne. l,68;9,l44, and 86,569, led February 3th, 1926, Patent No. 1,689,145. f l

ln my prior patent and copending applications above referred to, l have shown and described a hydraulic lift adapted particul'arly for elevatiiig'motor vehicles to facilitate servicing them and including a cylinder having a pluri er-piston therein adapted to be lifted by fluid pressure, a super-structure being supported by the upper end of the plunger and including a pair of parallel rails or runways upon which a motor vehicle or the like is adapted to rest. The plunger is adapted to be lifted to elevate the vehicle, whereby ins ections may be made of the underside o the vehicle and any desired work performed thereon, and the plunger and super-structure is adapted to be rotated whereby the apparatus maybe employed as a turn table. y

One lof the objects of myinvention is to pppvide an improved automobile-servicing Another object is to provide a lift of the single plunger type wherein the rigidity ot the plunger against lateral dis lacement is increased, particularly when elevated and while going up or down.

Another obJect is to provide multiple vertically-spaced bearings which permit ready vertical and rotary movements of the plunger while a'ording the plunger an eiective brace a ainst lateral inclination from eccentric loa' s or other causes. Y

Another object is to provide a plun er-y bearing unit which removably fits wit in the plunger cylinder and cooperates with the cylinder side wall to resist any side thrust from the plun er.

Another obJect is to provide a structure which readily lends itself to fabrication and relatively permanent co-relation of moving parts wherebyassembl transportationV and installation are simplified and cheapened.

A further object is to provide such an apparatus with means for indicating each operation oi' the device and the pressure necessary for each vehicle elevation whereby a. permanent record may loe kept of the operaen of to determine not only the number of times the apparatus has been operated, but also to permit him to obtain some ideav as to the weights and consequently the makes ot ve- @o hicles which have been elevated.

A further object is to provide a pair ol relatively wide rails or runways upon which the vehicle is adapted to rest whereby an operator may standV the runways beside the vehicle, novel ladders' and carrying means therefor being provided to permit the operator to gain access to the runways.

A further object is to provide an apparatus ro of the above mentioned character wherein the plunger and cylinder are adapted to contain oil or similar liquid and wherein fluid pressure is adapted to be introduced above the level of the liquid to edect the elevation 7s of the vehicle, and to provide a novel form of safety device to prevent the elevation of the vehicle when the level of the liquid therein falls below a predetermined levelB A further object is to provide an appae0 ratus of the above mentioned character provided with novel coactiiig jack means whereby either wheel of a vehicle arranged on the runways may be independently elevated to permit it to be revolved.

A further object i's to provide a novel :torni of chock to prevent a vehicle from rollin from the runways, the checks being adapte to be swung to initial operating positions to act as skids to permit a vehicle to bedriven upon the runways.

A further object is to provide a novel form of guide sleeve for the plunger whereby the latter may be successively elevated and lowered without scoring the sides thereof.

A further object is to provide an apparatus of the character just referred to .having a packing gland at the up er end ofthe ide sleeve and provided wi automatic ta e-up means.` l

or wall: upon ee A further object is to provide an apparatus of the character referred to wherein the various parts such as the plunger, guide sleeve and packing gland are readily accessible for making repairs'and replacements. f

A further object 1s to provide a super-4 and wherein each runway is arranged a substantial distance above the floor or other supporting surface-when the device is in lowered position, thus preventing lthe runways from descending upon and injuring' the feet of operators.

Other ob'ects and advantages of the invention wil become ap arent during the courseof the following escription.

In the drawings I have shown several einbodiments of the invention. In thisshowing',

AFi re 1 is a central vertical sectional view showing the apparatus in lowered osition, Fi 're 2 is a detail section o n line 2-2 of Figure 1,

Figure 3 is a central transverse sectional view showing the apparatus in elevated position,

Figure 4 is a plan view,

Figure 5 is a fragmentary sectional perspective view of a vehicleqack supporting member anda portion of the adjacent runwa lzigure 6 is an enlar ed central vertical sectional view of the cylinder and associated elements,

`rFigure 7 vis a detail section showing Ione end of one of the runways and its associated chock, p

y Figure 8 is a section` online 8-8 of Figi ure 4, v

Figure 9 is a fragmentar central vertical vsectional view of a modi ed form of the apparatus, i

Figure 10 is alcentral transverse vertical sectional view showing another modification of the apparatus, and,

Figure 11 is a detail section of the upper t end of theair pressure pipe.

Referrin to Figures 1 to 6 of the drawings, the numera 10 designates acylinder or casing which is embedded in a concrete or similar foundation orwell 11. The cylinder is preferabl formed of steel or similar tubing and it is c osed at its lower end by a head 12 which may be secured within the end of the cylinder by welding. An upper horizontal flange 13 is welded or otherwise secured to the upper end of the cylinder and projects outwardly therefrom.

A guide and bearing sleeve or cage 14 is arranged in the up ver end of the cylinder, and this sleeve is o substantial len h for a puipose to be described. As clear y shown in igure 6, the ide sleeve is provided at it upper end wit an outstanding flange 15 with babbitt or similar bearings 25, the

which is secured to the flange 13 by bolts or the like 16. The guide sleeve is recessed at its upper end to receive and provide an annular -seat for suitable packing 17 adapted to be compressed by a gland 18, the latter havin an outstanding an e 19 at its upper -en Means is provided or automatically maintaining the packing 17 under proper compression. As shown, a flanged cup 20 is 'arranged in the flange 19 in alinement with each of the bolts 16, the latter having upwardly extending ends 21 projecting t rough each of the cups. A c'oil spring 22 is arranged in each cup, and contacts at its upper end with a washer 23 held in position by an ladjusting nut 24. Obviously each spring contacts with the bottom of thecup in which it is arranged, tending to exert a downward pressure on the flange 19, and consequently the gland 18. The guide sleeve is provided within opposite ends guide sleeve being provided with internal groovesv 26 to receive a t'o maintain the bearings in position.

A plunger-piston 2 7 is adapted to reciprocate in the 1de sleeve 14. The plunger also is preferab y formed of steel or similar iping and fs. preferably partially close .at its lower end by a head 28 preferably welded thereto. The upper end of the plunger is closed by a head 29, and a filling plug 30 may be arranged in the center of this head. The cylinder and plunger are adapted to contain a li uid substantially to the level indicated -by t e dotted line 31 in Figure 6. The liquid employed is preferably lubricating oil, and whenthe .device is in operation, this oil is adapted to be utilized for spraying various parts of a vehicle, as will become apparent. A-pipe 32 is mounted in the head 29 and pro.- jects downwardly within the plunger toa point near the bottom thereof. This pipe is` adapted to supply lubricant to a hose 33 through a valve 34, the hose 33 bein provided with a spray nozzle 35 adapte to be controlled bg a manually operable valve 36, as shown in igure 1. Above the level of the oil, the pipe 32 is provided with a small openin 32 to provide an atomizing action for the oi spray means, and oil is admitted into the pipe through openings 33 in a suitable cap or the like mounted in the lower end of the pipe. p

A support indicated as a whole by the numeral 37 is arranged on the upper end of the plunger. This support includes a central cylindrical ortion or -head 38 surrounding the upper en of the plunger. The head 38 is split at one side as indicated at 39 and is adapted to be clamped in position on the plunger by a heavy bolt 40 as shown in Figure 4. Referring to Figure 6 it will be noted that the head of the support is provided with an internal flange or shoulder 41 which overlies the upper end of the plunger to prevent portion of the bearing metal Y a plurality of diverging arms 42 having parallel extensions 43 at their ends. The arms 42 are substantially U-shaped in cross section, and are provided, with openings for the reception of bolts 44 by means of which rails or runways 45 (preferably of substantially T-sha-ped cross section) may be secured v to the support. Each of the runways includes a relatively wide tread iortion 46 upon which a'vehicle is adapted to e driven, in a manner to be described, and further includes base portions or flanges 47 having slots 48 therein through which the bolts 44 extend. The slots 48 are provided to permit vertical adjustment of the runways. The runways are adapted to rest-upon a concrete foundation. floor or the like 49, when the device is in lowered position, as shown in Figure l, and it will be apparent that under such conditions, the tread portions 46 are arranged a slight distance above the support.

ln practice it has been found that workmen, standing near the apparatus while it is being lowered, are liable to injury by having their feet caught beneath the runways when the latter are lowered into contact with the surrounding support. With the present construction as above described, sucient space is left beneath thel runways to prevent the occurrence of such an accident Means are provided for introducing fluid pressure into the interiorof the lunger 27 to eect the elevation thereof. s shown in Figure 6, a plug 50 is arranged in the head 12 of the cylinder and supports an air pipe 5l, the lower end of the latter preferably being threaded in the plug. rlhe upper'end of the pipe 51 terminates above the level of the body of oil within the plunger and upon thc introduction of air into the plunger above` the oil therein, the pressure thereof elevates the plunger while the oilflows outwardly from the lower end of the plunger into the cylinder, in a manner to be described. An air supply pipe 52 also is threaded in the plug 50 to deliver air to the ipe 51. The pipe 5,2 extends transversely rom the casing l0 and then vertically parallel to the casing, as indicated at 53. The vertical portion of the pipe communicates at its upper end'w-ith a horizontal pipe 54 which extends parallel to the-surface of the concrete base49, as shown in Figure l. At its outer end, the pipe 54 turns upwardly as at 55 and connects to a T-joint 56, one side of which is connected to an exhaust valve 57 while the opposite side connects to an inlet valve 58. The latter valve is connected by a pipe 59 with a suitable source of air pressure such as is usually present at gasoline filling stations for the purpose of inflating tires, and for like uses. It will be apparent that when the valve 57 is closed and the valve 58 opened, air will be supplied under Vpressure to the interior of the plunger to liftthe latter, while the plunger and associated elements readily may be lowered by closing the valve 58 and opening the valve 57.

Means is provided for permitting a relatively free flow of fluid from the plunger to` the cylinder when the former is elevated and for restricting the flow of fluid from the cylinder to the plunger when the latter is being lowered. As shown in Figure 6, the pipe-51 extends through a relatively large opening 60 formed in the plunger head 28, and a fluid control member 61 is arranged in the opening 60. This control member or dill'erential valve includes a cylindrical stem 62 surrounding the pipe 51 and upper and lower heads 63 and 64. rThe pipe 51 fits fairly loosely withiny the stem 62 to permit 'the slow passage of oil therethrough. The lower head 64 is adapted to contact with the plunger head 28 whenthe' plunger is being lowered, while the upper head 61 contacts with the plunger head 28 when the plunger is being elevated. As clearly shown the upper head 61 is provided with openings 65 for the passage of oil when the plunger is being elevated. The structure and operation of the Huid control differential valve 61 are fully disclosed in my Patent No. 1,689,145 previously referred to. It will be apparent that when the plunger is being elevated, oil may flow freely through the openings 65 and through the space between the pipe 51 and the interior ofthe stein 62, while the imperforate head 64 contacts with the plunger head 28 to restrict the flow of oil when the device is being lowered, thus providing a dash pot action which would prevent the sudden falling of the plunger if a break should occur in the air line.

ln the operation of devices of this character, it has been found that operators fail to report all of the individual operations carried out by the apparatus, and accordingly means are provided for indicating each clevation of the plunger and the vgeneral character of the vehicle elevated, is indicated by the weight thereof. Referring to Figure 1, the numeral 66 designates a pressure pipe which is tapped into the casing 10. The opposite end of the pipe 66 is adapted to deliver pressure to an indicating gage 67 of any well known type which is adapted for per-forming the desired functions. In the type of gage preferred, a dial is provided which is cali brated as to time and pressure, and is provided with clock work and similar mechanism for moving the dial. It will be obvious that each time the plunger is elevated, the full pressure required to raise the plunger will be indicated upon the dial of the gage, and since different pressures are necessary for vehicles of did'erent sizes, it will be apparent that a clear idea of the characters of the vehicles operated upon may be gained,

from an examination of the indicator sheets. Suchsheets also will disclose the tune at 4 which each operation takes place. It will be keep a careful check upon the operators.

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with a tread portion 77 and side flanges 78 r ends, asl s As a further means for insuring the safety of operators and other persons whomay be near the apparatusV during its operation, means are provided for preventing the elevation of the plunger after the level of the oil drops below a predetermined point. Referring to Figure 6, the numeral 68 designates a pipe or similar tubular membery the upper end of which is threaded on the lower end of a plug 69, thelatter beingwthreaded a suitablel opening in the upper plunger Theplug 69 is provided with an opening 70 extending therethrough for the passage o air, in a manner to be described. The pipe 68 is provided beneath the plug 69 with a plurality of air openings 71 communicating with the interior of the plunger above the level of lthev oil therein. A valve 72 is arranged in the 'upper part of the pipe 68 and is secured to the upper end of a valve stem 73. A cork or similar float 74 is secured to the lower end of the valve stem 73 as shown. P

The lower'end of the pipe 68 is open, and the pipe is further provided with openings 75 just above the float 74. It will be appar ent that when the plunger is filled lwith oil to the proper level the float 74 will elevate the Valve `7 2 to a position aga-inst the lower end of the plug 69 to close the passage there- Re erring toFigures l; 4 and 7, the numeral 7 6 designates a plurality of combined approaches and chocks arranged on the ends of therunways 45. Each chock is provided which preferably diverge toward their' outer own in Figure 4. One of the flanges 78 is pivotally connected as at 79 with the flange 47 of each runway, while the other flange of each chock is pivotally connected as at 80 with a bracket 81 secured to each end of each of the runways. As shown in Figures 4 and 7, each chock is provided with a central'ofset extended portion 82 which is adapted to engage beneath the tread of each runway when the device is adapted to act as an approach, as indicated in dotted lines in Figure 7. The members 76 are adapted to be swung upwardly and inwardly to the solid line position shown in Figure 7 to act as chocks for the wheels of a vehicle arranged on the` runways. Further inward movement of the chocks is adapted to be-liinited by Contact between the tread portions thereof and bevelled edges 83 formed at the exhead 29 to be-supported thereby.`

f operator to work pair tremties of the flanges 47 and the brackets 8 s As shown in Fi `ures 3, 4 and 5, aljack support 84 is adapte to engage the upper portion of the flan e 47 of eit er runway. For this purpose, t e jack support is provided with a hanger 85 as clearly shown in i ure 3, and it willbe apparent that the ja! support is adaptedrto slide alon the flange of either runway whereby it may .arranged in any desired position. A 'pack 86 of any desired type may be arranged upon the, su port 84 whereby either end of either ax e of a vehicle may be elevated to permit the wheel to turn freely. The jack may be operated by a suitable handle 87. In Figure 3 I have shown one of the front wheels of a vehicle elevated by means of the jack 86 arranged on the support 84. n

The apparatus is adapted to elevate a vehicle to a substantial height to permit an freely thereunder, and occasionally it becomes necessary or desirable for an operator to am access to the runways and to the vehicle or various ur oses when they are elevated. According y provide a of ladders 88 having steps 89 .thereon and adapted to` be arranged in the` positions indicated in Figure 3. Each ladder is pivotally connected at one end as at 90 to a suport .91 which in turn is pivotall connected to one of the runways as at 92. hus it will be apparent that eitherladder is adapted to be raised to a horizontal position, and then to be swun in a horizontal plane to a osition beneat the runway as indicated in i ure 8, and hangers 93 are arran ed beneat the runways to support the la ders when they are in inoperative sition beneath the run-way treads. If des1red, the free end of each ladder may be rovidedwith casters 94 to facilitate outward) movement of the lower end in the event the plunger is lowered while the ladder is down.

In Figure 9 offthe drawings I have shown a somewhat modified form of apparatus which is adapted to be bodil removed from position when desired. Tn tllis form of the invention, the ,'plunger, operating elements, supporting head and runways, etc., are the same as in the form previously described, and need not be referred to in detail. In the modified formof the invention, the tubular casing 10 also is the same as in the form previously described, but in this case, a relatively large well 95 is employed, and the casing 10 is spaced a substantial distance from the walls of the well, for a purpose to be described. The casing 10 is Supported at its upper end by a clampingsleeve 96 which is split and adapted to be clamped about the casing by bolts 97. The sleeve is provided with a shoulder 98 which engages the lower face of a flange 98' to support the casing l() and is secured to the flange 98 by bolts 99 of a shallow pit Ql formed in the concrete at the upper end of the well. llhe Harige-101 is secured in position by anchor bolts 103 embedded in the concrete of the wall as clearly shown in Figure 9. Nuts 104 are arranged on the upper ends of the anchor bolts 108.

lln the present embodiment of the invention, the air supply pipe 53 is arranged in the space betweenlthe casingV 1 0 and the well 95, whereby it will be apparent that the anchor bolts are the only elements embedded in the concrete.

lie

ln Figure 10 of the drawings l have shown a further embodiment of thedevice which, in general, is particularly adapted for use in connection with one of the upper tloors of a garage or the like. The details of construction of this form of .the device are similar to the forms previously described and need not be referred to in detail. ln this form of the invention, uy rods 105 are embedded at their upper en s inthe floor 106, while. their lower ends are connectedto the'lower end oit the casing 10. Turnbuckles 107 are provided for tightening the gu rods. bviously the concrete well is eliminated in this forni of the invention. In connection with the clamping member 96, a supporting member 108 is employed which is bolted to the door of the building as at 109. lf desired, the lower plunger head may be eliminated and the entire lower head of the plunger le't open. 1n this torni of the device, a plug 110 is preferably threaded in the upper end of the air pipe 51, this plug being provided with a restricted opening 1 11 therethrough. Plfhe opening 111 is provided for preventing the rapid escape oi -air from the interior of the plunger if a break in the air line should occur. rlhe plug 110 also has been illustrated as asecondary safety device in the previously described forms ot, the apparatus. ln practice, both the plug 110 and the fluid control member 61 maybe employed, and the plug 110 is illustrated at the upper end of the air pipe 51 in each of the forms of the invention previously described.

ln each of the forms of the invention illustrated, a shallow pit of relatively small diameter surrounds the upper end of the cylinder, and it has been found that such pit advantageously may be employed for furnishing lighting .means for illuminating the lowerv portions of a vehicle. As shown in Figure 10, the pit may be recessed as at 112 and provided with lights 113, the upper portions of the recesses preferably overhanging the lights to prevent accidental damage thereto.

.quired will be registered on If desired, guards'114 ma the lights to afford ad itional protection thereto. i

The operation of the apparatus yis as tollows:

Referring to Figures 1 to 6 inclusive, it will be apparent that a vehicle may be driven into position on the runways by lowerin the 'chocks at either end of the apparatus. liter the vehicle is in position, the checks are swung inwardly to the dotted line position shown in Figure 1, whereupon the valve 5'? is closed, and the valve 58 opened. Conibe arranged over iti pressed air will be supplied to the interior of v the plunger above the level of the oil therein, and this pressure will elevate the plunger as will be apparent. of the plunger is limited by the engagement of the lower end of bearing cage 14 with the projecting ange of lunger head 28, which engagement under t e induence of the upward pressure ed'ectively assists in maintaining the plunger in a substantially vertical position when elevated. It will be apparent that the pressure required to elevate the plunger will depend 'upon the weight'ot the vehicle being elevated, and the pressure rethe gage 07 together with the time at which the operation takes place. The gage sheets therefore serve as a permanent record oi* the'operatioii's oil the characters ot the vehicles elevated may be determined trom the recorded pressures.

During the elevation ot the plunger, it will be apparent that the oil within the plunger will flow downwardly through the oil control device. The space between the stem 62 and pipe 51, and the passages provided by the openings 65 permit the dow of oil to take place freely, but the new ot oil troni the .cylinder into the plunger when the ap aratus is lowered will be retarded b upwar inovement of the oil control device whereby the oil is permitted to dow only through the restricted space between the pi e 51 and stem 62 of the -di'derential liuuidcontrol valve. 'lhus it will be apparent that in the event oi a failure of any part of the apparatus as would release air pressure therefrom while a worlrman is beneath the vehicle, such as` if a break should occur in the air line, a dash pot action is provided to l eatly retard downward movement oit the ve icle, thus providing ample time in which the opera-tor may escape from the working position referred to.

The lrelatively ,great vertical separation between and the length of the bearing surfaces provided by the guide sleeve 1li serve to insure lateral rigidity of the plunger and to prevent any undue lateral wear within the guide bearings, and the provision of' the babbitt metal or similar bearings within the guide prevents the scoring of thc surfaces of the plunger.` Thus it will be apparent that The maximum elevation Y the apparatus, and a fairly accurate idea ot or similar tubular material and is of u ni orrn internal diameter throughout. The support 37 at the upper end of the plunger readily may be removed merely by loosening the clamping bolt 40. The packing gland, clamping bolt nuts 24 and .the washers 23 then may be removed, together with nuts which engage the upper face of the flange 15, whereby the plunger and guide sleeve may be withdrawn from the up er end of the casing. Occasionally it is esired to remove the apparatus to a new position, and thisvmay be done by removing the elementsreferred to and fillin the opening within theempty casing 10. e latter elements are relatively inexpensive and readily may be replaced.

As previously stated, the pipe 32 extends downwardly to a point near the bottom of the plunger to receive oil therefrom for the pur vehicle. The valve 34 is opened, whereupon the operator may use the spray nozzle 35 for y spraying various parts of the vehicle, such as the springs, etc., and the flow of lubricant readilyl maybe controlled by the valve 36. The capacity of the plunger and cylinder is relatively large, and consequently comparatively small amounts of the oil will be used on ea'ch individual vehicle. It is desirable, however to replenish the oil from time to time, an also to prevent operation of the apparatus when the level of the oil falls below a predetermined point. The float 74 obviousl will be controlled according to the leve of the oil within the plunger. When a suicient quantity of oil is present, the valve 72 will remain seated against thelower end of the plug 69, thus preventing the escape of air therethrough when pressure is introduced into the lunger. However when the level of the oil)drops ioat also will drop and upon the introduction of pressure into the plunger, air pressure will escape through the opening thus preventing the device ,from operating. The plug 30 then may be removed in order to replenish the supply of oil.

When the plunger reaches its uppermost position, the flange of the lower cylinder head contacts with the lower end of the guide 14, and ably machined to provide a perfect contact to prevent the leakage of oil into the interior of the guide sleeve, thus preventing the escape of oil through theI packing gland and vtions when the apparatus is e oflubricating various parts of the an appreciable distance, the A these contacting surfaces are preferlparatus as a whole readily may be the subjection of the latter to the oil pressure. The sprin 22 serve to urge the gland 18 downward y to maintain the packing under pro er pressure. y l

e provision of the'slots 48, as shown in Figure 2, permits `the runways to be adjusted vertically within reasonable limits to accommodate the apparatus to slightly uneven suryfaces 'of the surrounding concrete 49. As

previously stated, the treads of the runwa s are relatively wide and are arranged a slig t distance above the surrounding concrete sur- 'face when theplunger is down, ingly it will be apparent that no injuiY can occur to the feet of operators when the e is lowered. The .members 76 are adapted to serve both as approaches and chocks asprevously stated. The offset portions 82 are adapted to engage the lower faces of the treads of the runwa s to limit downward movement of the members 76 to prevent them from assuming rvertically depending posievated, i the members are left in the full line position indicated in Figure 1. Thus the checks will not be injured'when the plungeris lowered.

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and accord- When employed as chocks, the tre'ad portions of the members 76 are adapted to engage the bevelled edges 83 of the runwa?1 flanges to limit the inward movement of t e checks as indicated in Figure 7. Occasionally it becomes desirable to elevate of a vehicle to permit it to turn freely, and accordingly the jack 86 support 84 are provided. It will be apparent that the hanger. 85 of the jack support permits .the latter to be arranged in se either of the runways whereby either vehicle wheel may be elevated The ladders 88 are provided as convenient meanswhereby an operator may gain access to the runways. Ordinarily these ladders are arranged in inoperative position closely beneath the runway treads, as shown in Fi 4 and 8. When it is desired to use the ladders, they may be swung outwardly in a horizontal plane about the axes of the bolts 92, and then the free ends swung downwardly about the hinges 90 to operative position as shown in Figure 3.

The operation of the form of the apparatus illustrated in Figure 9 is the same' asin t e 'form previously described. The modified form of apparatus, however, more readily js adapted to be removed. As clearly shown, the casing 10 is not embedded in the concrete well 95, butis supported in position wholly by the clamping member 96. The sleeve portion of this member is relatively long whereby the casing will be position. The separate elements of lthe apparatus such and guide bearing cage may the manner previously be removed in ",soved held rigidly in proper described. The apone of the wheels lected positions on asI the support 37 plunger 27 y and associated elements.

tus is adapted to be removed by disconnecting merely by removing the nuts 104, whereupon the casing may be withdrawn from the well. 'lhe casing or cylinder may be detached :from the clamping sleeve by loosening or removing the bolts 9?'. v

lt will be apparent that', with thc types of construction illustrated in Figs. 1, 3 and the plunger and guide-bearing cage may be together Withdrawn from the cylinder simply by the removal of the nuts which hold the bearing cage in place and then pulling the plunger from the cylinder.` This action is due to the fact that the projecting stop flange on plunger head 28 is adapted to engage the lower end of guide-bearing cage 14 and, when the cage retaining nuts on bolts 16 are removed, such engagement will cause the guidebearing cage to be drawn along with the plunger and consequently the pulling of the plunger out of the cylinder will likewise pull out the bearing cage.

'lhe form of the apparatus illustrated in Figure l is essentially the same as that illustrated in Figure 9 except that it'is adapted to be supported by the floor of a building. ln this case, the guy rods 105 arel employed tor anchoring the lower end of the casing The entire appara* the guy rods and removing the bolts 109. In this form of the apparatus, the lower plunger head and associated elements are eliminated and the restricted opening 111 alone is depended upon to provide a dash pot action to retard downward movement of the plunger if a break should occur in the air line. This vmeans oi" retarding downward movement of the plunger has been found effective, but as means for providing additional safety it is preferredy that the plug 110 and trol means previously describedboth be employed. The provision of the lights 113 atiords ample illumination for the lower side oi the vehicle when work is being performed thereon, and the arrangement of the lights within the recesses 113 prevents damage to the lights it a workman should step into the shallow Vpit surrounding the upper end ot the cylinder or it tools or the like should be dropped therein.l rll`he guards 11A provide additional protection for the lights.

lt is to be understood that the forms of the invention herewith shown and described are to be taken as preferred examples of the same and that various changes in the shape, size and arrangement ot parts may be resorted to without departing from the spirit orn theinvention or the scope of the subjoined claims.

l claim:

1. Apparatus of the character described comprising a cylinder, a plunger mounted to reciprocate vertically within said cylinder, means for supporting a vehicle on the upper end of said plunger, said cylinder and said the oil conplunger being adapted to contain a liquid,

means for introducing :duid pressure above the level of the liquid in said cylinder and said plunger, and means for preventing elevation of said plunger by permitting escape of fluid pressure when the level of the liquid is below a predeterminedv point.

2. Apparatus of the character described comprising a cylinder, a plunger mounted to reciprocate vertically within said cylinder, means, for supporting a vehicle on the upper end of said plunger, said cylinder and said plunger being adapted to contain a liquid, means for introducing fluid pressure above the level of the liquid in said cylinder and said plunger, and means for permitting fluid pressure to escape from the interior ot said plunger when'the levely of the liquid therem is below apredctermined point to prevent the elevation of said plunger.

3. Apparatus of the character described comprising a cylinder, a plunger mounted to reciprocate vertically within said cylinder, means for supporting a vehicle on the upper end of lsaid plunger, said cylinder and said plunger being adapted to contain a liquid, means for introducing fluid pressure a )ove the level of the liquid in said cylinder'and said plunger, said plunger being provided in its upper end with an opening communieating with the atmosphere, a valve normally closing said o' ening, and means for opening said valve w en the level of the Vliquid in said plunger is below a predetermined point.

v 4. Apparatus 'ci the character described comprising a cylinder, a plunger mounted to reciprocate vertically within said cylinder, means for supporting a vehicle on the upper end of said plunger, said cylinder and said plungerbeing adapted to contain a li uid, means for introducing iiuid pressure a ove the level of the liquid in said cylinder and said plunger the upper end ot said plunger being provi ed with an opening communieating with the atmosphere, a valve normally closingsaid opening and adapted to be held in normal closed position by the presence in the plunger and cylinder of liquid above a predetermined minimum level and liquid level falls below the predetermined level and thereby prevent 4introduction ot pressure fluid elevating the plunger.

5. ln a hoist, the combination ot an upright cylinder, a plunger slidable in said cylinder, load lifting and lowering means carried by said plunger, means to admit an operating' duid into said cylinder and to permit its discharge `therefrom to reciprocate said plunger, a guide-bearing supported in said cylinder for' said plunge-r, and means to remove said guide-bearing from said cylinder by the-removal therefrom of said plunger.

(5. In a hoist, the combination of an upright cylinder, a plunger slidable in `said cylinder, load lifting and lowering means carried by said plunger, means to admit an i operating fluid into said cylinder and to percompression ring,

mit its discharge therefrom to reciprocate said plunger, a plurality of guide-bearings supported in said cylinder for said plunger spaced apart vertically and connected together, and means to remove said guide-bearings from said cylinder by the removal of said plunger therefrom.

7. An automobile-servicing lift having an upright casing open at the top and closed at the bottom, a bearing cage insertable in the casing through its open end and providing vertically aligned and relatively widely separated bracing guide bearinvs below the open end of the casing, said cagecbeing braced laterally by the side wall of the casing, a plunger vertically and axially movable in said guide bearings and laterally braced thereby, packing between the plunger and bearing cage to form a pressure tight chamber within the casing, and means for subjecting the plunger to fluid pressure to elevate the same.

8. An automobile-servicing. lift having an upright casing, open at its u per end an closed adjacent its lower eng, a plunger mounted in the casing, a bearing cage insertable in the casing to surround the plunger and provide a laterally bracing plunger-bearing and a packing seat within the casing, said cage being laterally braced by contact with the side wall of the casing, a packing packing compressible between the packing seat and the compression ring to engage the plunger and form therewith a pressure tight chamber within the casing, and means for subjecting the plunger to fluid pressure to elevate the same.

9. An automobile-servicing lift comprising an upright cylindrical casing having an open top and closed bottom, a lunger mounted in the casing, a removable earing cage fitted wit-hin the casing to surround the lunger and provide therefor a laterally racing guide bearing a substantial distance below the open end of the casing and to provide a packing seat, the side wall of the casing a substantial distance below its open end being enga eable by the bearing cage to reinforce the ateral rigidity thereof, packing compressed against the packing seatand the plunger to form a pressure. tight chamber within the casing, means for communicating fluid pressure to the plunger to elevate the' same, and a vehicle supporting superstructure carried by the plunger.

10. An automobile-servicing lift comprising an upright cylindrical casing having an open top and a closed bottom, a plunger mounted inthe casing, said plunger having an outwardly extending projection, a bearing cage fitting within and removably attached to the casing to provide a laterally bracing ide bearinur around the plunger a substantial distance lielow the open end of the casing, said cage when attached to the casing forming an abutment for the projection on the plunger to limit the upward movement of and lend lateral rigidity to the plunger when elevated and the side wall of the casing serving as a reenforcement for the cage to resist lateral movement of the plunger, packing interposed -between the vcage and plun er to form a pressure tight chamber within the casing, means for applying a fluid pressure to the plunger to elevate the same, and a vehicle supporting superstructure carried by the plunger.

11. An automobile-servicing lift including an o en topped closed bottomed upright casin aving an outwardly projecting 4flange ad]acent its open end, a plunger in the casing, a plunger bearing cage projecting into the open end of the casing around the plunver and aving a flanve overlying and rigidly attachable to the ange of the casing, the bearing cage being engageable with the side wall of the casing to increase lts lateral rigidity and having a seat lfor -retaining packing, a packing ring having a flange overlying the flange o the bearing cage, packing interposed between the packing seat and packing ring to form a pressure ti ht chamber within the casing, and means for communicating fluid pressure to the plunger to elevate tho same.

12. A -rotary lift comprising an open topped closed bottomed tubular casing having an outwardly projecting annular flan adjacent its op'en end, a-plunger, a removab e guide bearing cage, anchored within the casing around t e plunger to laterally brace the plunger and provide a packing sea-t, a pack,- ing retaining ring overlying and bolted to the casing flange, packing interposed between the packing seat and packing ring in contact with the plunger to form a pressure tight chamber of the casing, and means for subjecting the plunger to fluid pressure to elevate the same. y

13. A rotary lift topped closed bottomed upright casing having an outwardly projecting annular flange 'adacent its open end, a plunger, a removab e bearingl cage having an annular flange overl ing t e flange of the casing and two annu ar verticali aligned but relatively widely separated gearings fitting around the plunger within the casing, the side wall of the casing bracing laterally the cage therewithin and the cage having a packing seat, a flanged packing-retaining and compressing ring, packing interposed between the packying seat and packing ring, means for anchoring together the flanges of the casing, bearing cage and packing ring and pressing the packing about the plunger to form of the casing a pressuretight chamber, and means comprising an open' issmoo for subjecting the plungor io uicl pressnrs to elevato 'the same.

ll. An .automobile-servicing lift having in combination an upright cylinder, s piango? slidololc in ills cylinder and rota-table about ill-is axis ilncrso'f, o removable bearing cage supporocl Within bloc cylinder and gaining lacral support from con'taci with the sitio rl/:ill iliorcof, said oen-ring cago acting upon che plunger to liolcl 'the same laterally rigid, moans for securing the 'bearing cage wit in' 'tho cylinrler, c projection on tico plunger for engaging the bearing cago to limit upward movement of the plunger when the bearing cage is secured Within lhs cylindcr and to wifclidrsw ills bearing cago from clic cylinder wllsn the looming cago is nnsecnrsfl ond the loclow inc open ond, said bearing cago also.

plunger is raised? means for imparting liuicl pressure to 'the plunger 'to Elevato die sains and for withdrawing tho :fluid pressure to pcrmii olio plunger lo clcsccnfl9 and s vehicle supgnoring superstructure carried oy thc plungero loi rotary lifi having in combination on upright cylinder, s removable bearing cage lying within and snp` orlzcfl by 'ons cylindsra moans for rigidly lio ding clic bearing cago in thc cylinder, s plungor sliflsbls in ills bearing cage and laterally suppoi'cil thereby, a projection on thc plunger ongcgeablc Willi ihe bearing cago lo limit *the uk Ward movemons -oif'chc'plungcr when "the caring cog@ is Tnclfi Within ille cylinder cnil io Withdraw 'hc bearing cago from clic cylindcr when they sro not retained together snol che plunger is raised, and means for imparting -`zo anfl witlo- Clrswing from the luncr the cfisccs ci iinicl pressure whereby le plunger is classical and lowcrcrl.

18. A rotary lift homing in combinsfnion an u righi casing, s removable bearing cago within the casing and in contraciabl-e relazion to the side Wall thereof so thai lateral throes upon the bsaring'cago may be resisted by clic casing, means for rigidly retaining the bearing cago within thc casing, s, plunger slialily and rotatably mounted in tho bearing cago and laterally supportati thereby, a jjorojcction on the plunger to strike thc bearing cage and "clica-shy limit ille elevation of lie plunger when the bcaring cage is retaine Within tine casing and to remove the bcarin cago from tho casing when it is not retaine tlicrein and the longer is rcmovcd there 4from, and connections whereby fluid proure may be applied lo and withdrawn from the plunger to clava@ and permit depressionV of clio plunger. f 1?.. n automobile-servicing lift compris ing an upright cylinder open at ons ond and closc adjacent the other ond, s, removable bearing osgc-insertble within thc cylinder in contracisblo relation to tine side Wall thoreo so Tchat sido thrust is imparted so mul reslated by the sido wall a substantial distance 

